1995 evinrude 60hp triple need more power ?

[phillnjack]

High guys
i have a evinrude 60hp triple, year is 1995 and i think 56 ci .
Apart from 70hp carbs, what else can i do that wont involve taking the engine fully apart and
doing very serious mods, as im not an engineer and dont have any specialist tools to hand.

ive got to get atleast another 5mph to race against my friends boat, he has my old 17ft picton gts boat and put
his 1977 140hp cross flow johnson on it.
He cant beat me from the take off, but has around 4-4 mph on me at top speed running his 17 inch pitch prop.

At the moment im running this engine on a 13 foot dory with 20 inch transom, very similar to a classic boston whaler 13.
the boat weighs 530 pounds on its own, engine is supposed to be 250 pounds, and i weigh around 235 pounds.
Extra weight is battery and fuel so around another 86 pounds...
total all up running weight is around 1100lbs or 500 kilo.
With the engine up one notch im getting around 42-44 mph with a omc sst 13x 19 prop and
35.6 mph with a 13/14x15 omc alloy prop.
It gets to the top revs in no time at all, cant even give it full throttle at the start as its a
proper monster from the word go, the boat is on the point of flipping backwards it acellerates so fast.
what i would like is to hit the magic 50mph with this boat if possible without going to crazy on the mods.

The engine is a 100% stock engine just as it left the factory, comp test shows 147 145 148 warm engine.
The only thing difference is the Vro has been taken off and running old style fuel pump as i dont trust the
Vro and all its components.
I run 50-1 mix on either quicksilver or evinrude 2 stroke oil .

im not 100% on what the top revs are but this engine is revving realy high,will get rev counter sorted out soon as need new rectifier.
But its definitely not lacking revs, if anything its over revving at the moment.

what size prop can this engine realy take ?
and is there any reasonably cheap mods i can make to it ?

any genuine ideas appreciated


phill

[sharpeye Mike]

What rpm are you running with the 19" prop ? Raising the motor on your transom will make a big difference on top speed but I'm not sure you will gaine 8 mph.
If this was my boat that's where I would start and than I would try different props, oh and get rid of every thing you don't need in your boat, that would include seats and what ever else, keep it light.
Mike

[phillnjack]

at the moment the cavitation plate is about 1/2 above the bottom of transom.
would up another 2 inches make that much difference ?
if so about how much 1mph ? 2mph ? 3mph ? at a rough guess ?

im not 100% sure what revs are at full throttle but i would say atleast 5500, it realy does get there fast and i think maybe even over revving.
as with 2 people it dont go any slower top end and still screaming !!!!

could this engine be able to run a 23 inch pitch prop ?
or if i get 70hp carbs what sort of extra speed ?


this week i plan on getting the rev counter up and working if possible.
i do know for sure it goes over 42 mph. ran on gps two ways on river and took the middle as average.

phill

[sharpeye Mike]

The higher you go, the more pitch you will probably need. Raise it 4 to 5", I can almost say you will gaine 4 to 5 mph but the only way to know is to try it.
A water pressure guage is a cheap ins., easy to install, just tee in to the pee line, some racers just run the pee hose in front of them so they can keep an eye on things. I gained 4 mph on 17' fishing boat powered by a 70 hp Johnson doing the same thing, then I came across an 19 pitch omc sst2 prop and gaine another 2 mph, I went from 36 to 42 mph, keep in mind this is a big aluminum boat with out the best bottom. I have a feeling you mite do better. Keep in touch when you do.
Mike

[phillnjack]

well i thought i would post back on this with some rotten results.

i took the whole boat apart and put in a new stronger transom, got the rev counter working properly and then went
out and got a few extra props and done some testing.

By raising the engine up as far as it will go on the holes ive lost speed, around 3 mph.

i will see about getting a jackplate and maybe post some results, so ive not forgotten this topic, just not
yet got the jack plate sorted out and tested.

phill